Changes in sodium appetite evoked by lesions of the commissural nucleus of the tractus solitarius

Changes in sodium appetite evoked by lesions of the commissural nucleus of the tractus solitarius

Author Ogihara, Cristiana Akemi Autor UNIFESP Google Scholar
Schoorlemmer, Gerhardus Hermanus Maria Autor UNIFESP Google Scholar
Colombari, Eduardo Autor UNIFESP Google Scholar
Sato, Monica Akemi Autor UNIFESP Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Faculdade de Medicina do ABC Departamento de Fisiologia
Abstract Ablation of the area postrema/caudal nucleus of the tractus solitarius (NTS) complex increases sodium intake, but the effect of selective lesions of the caudal NTS is not known. We measured depletion-induced sodium intake in rats with electrolytic lesions of the commissural NTS that spared the area postrema. One day after the lesion, rats were depleted of sodium with furosemide (10 mg/kg body weight, sc) and then had access to water and a sodium-deficient diet for 24 h when 1.8% NaCl was offered. Water and saline intakes were measured for 2 h. Saline intake was higher in lesioned than in sham-lesioned rats (mean ± SEM: 20 ± 2 vs 11 ± 3 mL/2 h, P < 0.05, N = 6-7). Saline intake remained elevated in lesioned rats when the tests were repeated 6 and 14 days after the lesion, and water intake in these two tests was increased as well. Water intake seemed to be secondary to saline intake both in lesioned and in sham-lesioned rats. A second group of rats was offered 10% sucrose for 2 h/day before and 2, 7, and 15 days after lesion. Sucrose intake in lesioned rats was higher than in sham-lesioned rats only 7 days after lesioning. A possible explanation for the increased saline intake in rats with commissural NTS lesions could be a reduced gastrointestinal feedback inhibition. The commissural NTS is probably part of a pathway for inhibitory control of sodium intake that also involves the area postrema and the parabrachial nucleus.
Keywords Nucleus of the solitary tract
Sodium appetite
Sucrose
Furosemide
Language English
Date 2009-06-01
Published in Brazilian Journal of Medical and Biological Research. Associação Brasileira de Divulgação Científica, v. 42, n. 6, p. 561-566, 2009.
ISSN 0100-879X (Sherpa/Romeo, impact factor)
Publisher Associação Brasileira de Divulgação Científica
Extent 561-566
Origin http://dx.doi.org/10.1590/S0100-879X2009000600014
Access rights Open access Open Access
Type Article
Web of Science ID WOS:000266135800002
SciELO ID S0100-879X2009000600014 (statistics in SciELO)
URI http://repositorio.unifesp.br/handle/11600/5090

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